preparing no-migration demonstrations for …...level of detail of information required for a nmd....

Printed on paper that contains at least 30 percent postconsumer fiber

United StatesEnvironmental ProtectionAgency

Solid Waste andEmergency Response(5305W)

EPA530-R-99-008February 1999www.epa.gov/osw

Preparing No-MigrationDemonstrations forMunicipal Solid WasteDisposal Facilities:A Screening Tool

Preparing No-Migration Demonstrations

for Municipal Solid Waste Disposal

Facilities - A Screening Tool

December 1998

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DISCLAIMER

The information in this document has been funded wholly or in part by the U.S. Environmental Protection

Agency (EPA) under Contract Number 68-W5-0057. Mention of trade names or commercial products does

not constitute endorsement or recommendation for use.

NOTICE

The policies set forth in this manual are not final EPA actions, but are intended solely as guidance. They are

not intended, nor can they be relied upon, to create any rights enforceable by any party in litigation with the

United States. EPA officials may decide to follow the guidance provided in this manual, or to act at variance

with the guidance, after analysis of specific site circumstances. EPA also reserves the right to change this

guidance at any time without public notice.

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TABLE OF CONTENTS

Section Page

1.0 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

2.0 STEP 1: MAKE AN EARLY DETERMINATION OF ELIGIBILITY . . . . . . . . . . . . . . . . . . . . . . 4

2.1 RECENT CHANGES IN FEDERAL REGULATIONS GOVERNINGSMALL, DRY, REMOTE MSWLFs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2.2 DETERMINATION OF AN MSWLF'S ELIGIBILITY FOR ANO-MIGRATION EXEMPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.2.1 Key Screening Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52.2.2 Analysis Against Key Screening Criteria for MSWLFs That

Have Received Exemptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62.2.3 Estimation of Time of Travel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.3 CONTENT OF A NMD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3.0 STEP 2: ESTIMATE AND ANALYZE THE COST OF THE NMD . . . . . . . . . . . . . . . . . . . . . . 20

3.1 ESTIMATE THE COST OF A NMD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203.2 ANALYZE THE COST OF THE NMD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

4.0 STEP 3: FOLLOW COST-EFFECTIVE METHODS OF PREPARING THE NMD . . . . . . . . . . 24

4.1 PREPARE A CLEAR WRITTEN DESCRIPTION OF NEEDS . . . . . . . . . . . . . . . . . . . . 244.2 DISCUSS NEEDS WITH CONSULTING FIRMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244.3 SELECT A CONSULTANT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

LIST OF TABLES

Table Page

2-1 SUMMARY OF RESULTS OF AN INFORMAL ANALYSISOF 17 SUCCESSFUL NMDs IN SEVEN STATES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2-2 SOURCES OF SITE-SPECIFIC DATA ON KEY VARIABLES USED TO EVALUATE NO-MIGRATION DEMONSTRATIONS . . . . . . . . . . . . . . . . . . . . . . . 12

2-3 PERMEABILITY RANGES FOR VARIOUS TYPES OF SOILS . . . . . . . . . . . . . . . . . . . . . . . . . 13

2-4 MATRIX FOR GROSS ESTIMATING OF THE VELOCITY OF MIGRATIONOF HAZARDOUS CONSTITUENTS TO THE WATER TABLE . . . . . . . . . . . . . . . . . . . . . . . . 15

2-5 NMD DATA COLLECTION FORM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

3-1 RATES FOR COSTING VARIOUS ON-SITE MEASUREMENTSTHAT MAY BE REQUIRED BY THE STATE (1996) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

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LIST OF FIGURES

Figure Page

2-1 DECISION TOOL FOR DETERMINING THE PROBABILITYOF A SUCCESSFUL NMD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

APPENDICES

Table Page

A-1 CRITERIA USED BY STATES TO MAKE DETERMINATIONSABOUT NO-MIGRATION EXEMPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

A-2 VALUES FOUND FOR KEY PARAMETERS IN SUCCESSFUL NO-MIGRATION DEMONSTRATIONS FOR SPECIFIC MSWLFS IN ARIZONA,IDAHO, MONTANA, NEVADA, NEW MEXICO, UTAH, AND WYOMING . . . . . . . . . . . . . A-4

A-3 COMPARISON OF PARAMETERS AND VALUES USED BY EACH STATE . . . . . . . . . . A-11

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1.0 INTRODUCTION

Federal regulations [40 Code of Federal Regulations (CFR) 258.50(b)] allow owners and operators of

municipal solid waste landfills (MSWLF) to prepare a demonstration which, if successful, results in the

exemption of the MSWLF from groundwater monitoring requirements. The demonstration is commonly

referred to as a no-migration demonstration (NMD). The applicable federal regulations are as follows.

Groundwater monitoring requirements under 40 CFR 258.51 through 40 CFR 258.55 of this part

may be suspended by the Director of an approved State for a MSWLF unit if the operator can

demonstrate that there is no potential for migration of hazardous constituents from that MSWLF unit

to the uppermost aquifer (as defined in 40 CFR 258.2) during the active life of the unit and the post-

closure care period. This demonstration must be certified by a qualified groundwater scientist and

approved by the director of an approved State, and must be based upon:

(1) Site-specific field collected measurements, sampling, and analysis of physical,chemical, and biological processes affecting contaminant fate and transport, and

(2) Contaminant fate and transport predictions that maximize contaminant migrationand consider impacts on human health and the environment.

States are not required to incorporate these Federal performance standards into their permitting standards.

Individual states may allow exemptions based on NMDs, but states are not required to consider such

demonstrations. States that do consider NMDs must use criteria that are at least as stringent as the Federal

criteria. Because the federal regulations are performance standards, they allow states considerable flexibility

in the choice of the criteria and methods used to evaluate no-migration demonstrations. This means that

decisions about NMDs can differ from state to state, as can requirements governing the amount of data and

level of detail of information required for a NMD. Many site-specific factors will influence the amount of

information required to support a decision about a NMD, including predicted time of travel for hazardous

constituents and other conditions.

This guidance is intended to be a screening tool to be used by owners and operators of MSWLFs to rapidly,

but tentatively, determine their likelihood of preparing a successful NMD. Such rapid screening is expected

to save significant time and money when the MSWLF clearly does not meet the applicable performance

standards. Alternatively, the use of this guidance may result in little or no time or cost savings for those

owners and operators whose MSWLFs fall just short of meeting the performance standards.

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This guidance is a screening tool; it does not present in-depth discussions of technical, site-specific factors

that must be measured and modeled during the latter stages of preparing a NMD. However, in-depth analysis

of site specific data is a very important process and EPA expects that no NMDs would be approved without

it. Obtaining site-specific data can be expensive and time-consuming. By using this guide, owners and

operators of MSWLFs can evaluate the likelihood of success of the NMD and decide if collecting site-

specific data is likely to be worthwhile.

This guidance is not intended to encourage or discourage owners and operators of MSWLFs from submitting

NMDs to their respective states. It does not provide a definitive process for issuing a no-migration

exemption. A MSWLF that is a good candidate for a successful NMD according to this guidance may later

be rejected from such consideration based on more detailed sampling and analysis. The main goal in

preparing this guidance is to present a profile of information from 17 NMDs filed by owners of MSWLFs

who were successful in securing no-migration exemptions. The information was obtained from the files of

seven states: Arizona, Idaho, Montana, Nevada, New Mexico, Utah, and Wyoming. The guidance is based

on the characteristics of these 17 successful NMDs and provides a practical, step-by-step approach for

applying major screening factors. The States through their permitting programs, not the U. S. Environmental

Protection Agency (EPA), issue the no migration exemptions. This guidance compares successful NMDs to

the Federal criteria. A favorable rating in this screening process does not guarantee that an owner or operator

will be able to make a successful NMD.

The audience for this guidance is limited. The audience is composed primarily of those relatively small

MSWLFs in dry areas (generally west of the Mississippi River) that do not meet the criteria for a “small and

dry” landfill that are eligible for an exemption from the groundwater monitoring requirements contained in

the MSWLF criteria [40 CFR § 258.1(f)(1)]. When this guidance was initiated, the exemption for small

MSWLFs in dry areas had been vacated as a result of a court ruling. The exemption was reinstated on

September 25, 1996.

This guidance contains a three-step process that allows evaluation of the chances of success and supports

decisions about whether to continue or to abandon the NMD process, as information is collected. The three

steps are presented in Sections 2.0 through 4.0 of this document, which are summarized below.

• Section 2.0: Step 1 - Make an Early Determination of Eligibility: Step 1 is an initialscreening step that has three main parts. First, the recent reinstatement of the exemption forsmall, dry, remote MSWLFs is explained. For MSWLFs that are not eligible for thatexemption, collection of preliminary data to assess the potential for a no-migration

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exemption is discussed. The final part of Step 1 describes the roles of the state or tribalauthorities in the NMD process and offers some practical advice about learning aboutpolicies, requirements, and information resources.

• Section 3.0: Step 2 - Estimate the Cost of a NMD: Step 2 helps build a simple estimateof the cost of preparing a NMD. The estimate will include the cost of obtaining regional andsite-specific information necessary for the demonstration process. The estimate alsoconsiders the costs of preparing the necessary report, including analytical and reportpreparation support from a consultant.

• Section 4.0: Step 3 - Collect and Analyze Information and Data and Write theDemonstration: Step 3 is a guide to selecting and working with a consulting firm to planfor the collection and evaluation of data and to preparing the NMD.

The approach set forth in this guidance should enable the owner or operator of a MSWLF to pursue the early

decision-making stages of a no-migration demonstration as efficiently and inexpensively as possible. The

approach relies on early warning signs that can lead to early abandonment of the effort.

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2.0 STEP 1: MAKE AN EARLY DETERMINATION OF ELIGIBILITY

This section has three subsections. Section 2.1 describes the exemption from groundwater monitoring

requirements for small MSWLFs in dry and remote areas. MSWLFs that qualify for and are located in states

that allow this reinstated exemption need not consider a NMD because they are already exempt from

requirements for groundwater monitoring. Section 2.2 introduces key hydrogeologic parameters used in

collecting preliminary data to assess the potential that a MSWLF may be a good candidate for a NMD.

Section 2.3 then discusses the role of state or tribal authorities in the NMD process. The discussion includes

some practical advice for learning about policies, requirements, and information resources.

2.1 RECENT CHANGES IN FEDERAL REGULATIONS GOVERNING SMALL, DRY,REMOTE MSWLFs

The Land Disposal Program Flexibility Act of 1996 directed EPA to reinstate the groundwater monitoring

exemption for certain small qualifying MSWLFs that had been vacated by a court decision. Rule changes

were promulgated on September 25, 1996 (61 FR 50410). These regulations, if implemented by the States,

would exempt an estimated 800 qualifying small MSWLFs from groundwater monitoring for MSWLFs that

are “small and dry” or “small and remote.”

A “small and dry ” MSWLF, by definition, receives an annual average of 20 or fewer tons of waste per day,

is located in an area that annually receives 25 or fewer inches of precipitation, and must exhibit no evidence

of contamination of groundwater at the site. All such MSWLFs are in the western United States.

EPA's definition of a “small and remote” MSWLF is one that receives an annual average of 20 or fewer tons

of waste per day, serves a community that each year experiences an interruption of surface transportation of

at least three consecutive months' duration, exhibits no evidence of contamination of groundwater at the site

and must serve a community that has “no practicable alternative” to landfilling of its municipal solid waste.

Almost all such facilities are in the state of Alaska.

The exemptions described above, known as the small-dry-remote exemptions, are valid under federal

regulations; however, no state is required to allow similar exemptions. A state can establish additional

requirements for obtaining small-dry-remote exemptions, if that particular state will grant such exemptions at

all. It is likely, however, that a state will base its decisions about exemptions on criteria that closely resemble

those applied under federal regulations. Owners and operators of MSWLFs must work with state authorities

to determine whether a particular facility is eligible for a small-dry-remote exemption. MSWLFs that are

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eligible for such exemptions need not pursue a NMD because they are already exempt from requirements for

groundwater monitoring.

2.2 DETERMINATION OF AN MSWLF'S ELIGIBILITY FOR A NO-MIGRATIONEXEMPTION

This section first describes key screening criteria that can be used in determining whether a MSWLF is a

candidate for a no-migration exemption. It then explains how to compare some key characteristics of a

facility with those of a number of other facilities that have received exemptions. Such a comparison can help

the owner or operator determine the probability that a NMD will be successful. The section then describes

how to calculate a conservative estimate of time of travel for hazardous constituents from the facility to the

uppermost aquifer.

2.2.1 Key Screening Criteria

The five variables that significantly influence the time of travel of leachate from a MSWLF to the uppermost

aquifer are the depth to groundwater, the permeability of the soil, the precipitation rate, the

evapotranspiration potential, and the net infiltration rate. Therefore, these variables can be used at a

particular MSWLF as key screening criteria for determining the eligibility of a MSWLF for a no-migration

exemption. These criteria depend almost entirely on site-specific conditions and their use requires on-site

measurements. In the following paragraphs, each of the five variables is described.

The depth to groundwater is the distance from the bottom of the MSWLF to the first layer of saturated soils

that are capable of yielding significant quantities of water. Some state regulations define this saturated layer

differently, depending on the quality of the groundwater and the quantity of groundwater yield.

The permeability of the soil refers to the rate at which water travels through it under saturated flow

conditions. Permeability generally is measured in centimeters per second (cm/sec), but also can be measured

in feet per year, with one foot per year roughly equivalent to 1 x 10 cm/sec.-6

The precipitation rate is the amount of rain received at a MSWLF over a given time period. It usually is

expressed as inches per year, but generally is averaged over a large number of years to account for annual

variability.

This analysis was conducted using only the data found within the main portions of 17 applications for NMDs. Some of1

the NMD applications did not contain data on one or more subject areas that were selected for the analysis. Although such data mayhave been available to and used by state officials in evaluating those applications, the collection and summary of such data are beyondthe scope of this report.

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The evapotranspiration potential is the maximum amount of water that could be lost from the soil by the

actions of direct evaporation and transpiration through the leaves of vegetation in a given area. It is

estimated based on such variables as average annual temperatures and humidities.

The net infiltration rate is the percentage of precipitation that enters the soils in a given area. The rate

represents the portion of rain water that does not run off the area and that is not evaporated or transpired.

At MSWLFs in areas that generally have significant infiltration, leachate will be formed and will move

toward the groundwater. At MSWLFs in areas in which there is little or no infiltration, there will be little or

no leachate generation, and little or no movement of leachate toward the groundwater.

2.2.2 Analysis Against Key Screening Criteria for MSWLFs That Have ReceivedExemptions

Presented below are the results of an informal analysis of 17 NMDs filed by owners of MSWLFs who were1

successful in securing no-migration exemptions from requirements for groundwater monitoring at their

facilities. Information about the 17 NMDs analyzed was obtained from the files of seven states: Arizona,

Idaho, Montana, Nevada, New Mexico, Utah, and Wyoming. In Montana, there were 6 successful NMDs; in

Wyoming, 3; in Idaho, 3; in Utah, 2 and in Arizona, Nevada, and New Mexico, 1 each.

Table 2-1 summarizes the results of the informal analysis of successful NMDs (Appendix A provides a

summary of criteria used by states to make determinations about such demonstrations and site-specific data,

as well as a comparison of parameters and values that were used in the analysis). Through review of the

table, it is possible to make the following general observations about the characteristics of the 17 MSWLFs

for which NMDs were analyzed:

• Large MSWLFs (those that receive more than 20 tons per day) and small MSWLFs (thosethat receive less than 20 tons per day) submitted 75 and 25 percent of the NMDs,respectively (8 MSWLFs submitted data on waste acceptance rates).

• The values for the criteria set forth in Table 2-1 do not appear to differ significantly betweenlarge and small MSWLFs.

• Annual precipitation is less than 15 inches at more than 93 percent of the MSWLFs and lessthan 25 inches at all the MSWLFs. Therefore, all the MSWLFs meet the definition of “dry”from the Federal criteria (16 NMDs included data on annual precipitation).

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TABLE 2-1: SUMMARY OF RESULTS OF AN INFORMAL ANALYSISOF 17 SUCCESSFUL NMDs IN SEVEN STATES1

(Page 1 of 2)

CRITERION SELECTED FOR ANALYSIS VALUES FOUND IN NMDs MSWLFs (State)2NUMBER OF LOCATIONS OF MSWLFs

SIZE OF MSWLF < 20 MT(Tons per day)

2

> 20 ID, NM, UT, WY6

NI AZ, ID, MT, NV, UT2 9

AVERAGE ANNUAL PRECIPITATION < 5 NV(Inches)

1

6 - 10 AZ, ID, MT, NM, UT, WY7

10.1 - 15 ID, MT, WY7

< 25 UT1 3

NI WY1

MINIMUM DEPTH TO GROUNDWATER (Feet) < 50 AZ, MT, UT4 4

51 - 100 MT, WY3

101 - 200 WY1

201 - 300 ID, MT3

301 - 400 ID, MT, UT3

> 400 ID, NM, NV3

MAXIMUM SOIL PERMEABILITY (Feet/Year) < 0.01 ID1

0.01 - 0.1 UT, WY2

0.11 - 1.0 MT4

1.1 - 10.0 UT1

10.1 - 100 ID, MT, NM5 3

101 - 1000 ID, NV, WY6 3

> 1000 AZ, WY7 2

NI MT1

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1. The states and number of MSWLFs included in the analysis are: Arizona (1), Idaho (3), Montana (6), Nevada (1), New Mexico (1), Utah (2), and Wyoming (3).

2. NI = Not available for one or more MSWLFs 3. Data on precipitation at one MSWLF was reported as a range of 6 to more than 25 inches; therefore, average annual precipitation was assumed to be less than 25 inches. 4. The depth to groundwater at the MSWLF in Arizona ranged from 18 to 160 feet; the range was 6 to 30 feet at a MSWLF in Montana, and 35 to 80 feet at a MSWLF in Utah. 5. Soil permeabilities ranged from 10 to 100 feet per year at one MSWLF in Montana and from 0.001 to 100 feet per year at one MSWLF in Idaho.6. Soil permeabilities ranged from less than 0.001 to approximately 150 feet per year at a MSWLF in Idaho, from less than 0.01 to 1000 feet per year at an MSWLF in Nevada, and from 2

to approximately 200 feet per year at an MSWLF in Wyoming.7. Soil permeabilities ranged from less than 1 foot per year to approximately 5,200 feet per year at a MSWLF in Wyoming.8. The cost of preparation of the demonstration could not be separated easily from the costs of other activities that were conducted at the site.

TABLE 2-1: SUMMARY OF RESULTS OF AN INFORMAL ANALYSIS OF 17 SUCCESSFUL NMDs IN SEVEN STATES

(Page 2 of 2)

CRITERION SELECTED FOR ANALYSIS VALUES FOUND IN NMDs MSWLFs (State)2NUMBER OF LOCATIONS OF MSWLFs

HYDROGEOLOGIC MODELS INCLUDED 8 AZ, ID, NM, NV, UT

NOT INCLUDED 6 MT

NI 3 WY

AVERAGE ANNUAL EVAPOTRANSPIRATION 30 - 40 2 ID, WYRATE (inches)

41 - 60 5 ID, MT, UT

61 - 95 2 AZ, NM

NI 8 MT, NV, WY

NMD COSTS < 5 2 AZ , MT(x $1,000)

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5 - 10 2 MT, NM

11 - 20 2 UT

21 - 30 2 ID, MT

84 1 ID

240 1 ID

NI 7 MT, NV, UT, WY

Notes:

The decision tool in Figure 2-1 was developed using all available data regarding four key screening criteria from 172

successful NMDs. Data regarding average annual precipitation was not available in one NMD. Another NMD did not contain anydata regarding soil permeability, and eight NMDs did not contain data regarding average annual evapotranspiration. These missingdata may have resulted in a reduction in the accuracy of the decision tool, however any such reduction is expected to be slight becausethe eight NMDs that lacked average annual evapotranspiration rates are associated with three states (Montana, Nevada, andWyoming) that would be expected to have evapotranspiration rates that are similar to those reflected in NMDs that contained dataregarding evapotranspiration.

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• Depths to groundwater exceeded 50 feet at more than 76 percent and 200 feet at more 53percent of the MSWLFs analyzed. (All 17 NMDs included data on depth to groundwater).

• Maximum soil permeabilities (or hydraulic conductivities) were equal to or less than 1 footper year (1 x 10 centimeter per second [cm/sec]) at 44 percent of the MSWLFs, and less-6

than 10 feet per year (1 x 10 cm/sec) at 50 percent of the MSWLFs. However, at 31-5

percent of the MSWLFs, maximum permeabilities exceeded 100 feet per year (1 x 10-4

cm/sec) (16 NMDs included data on maximum soil permeabilities).

C Annual evapotranspiration rates were equal to or greater than 30 inches at all MSWLFsanalyzed, exceeding 40 inches at 78 percent of MSWLFs analyzed (9 NMDs included dataon evapotranspiration).

• Models were included in 57 percent of the NMDs. The 8 that included models all used theHydrologic Evaluation of Landfill Performance (HELP) model.

• At 80 percent of the MSWLFs, the cost of a NMD was less than $30,000 (cost informationwas available for 10 demonstrations).

Owners and operators that already have reasonable estimates of annual precipitation, annual evapo-

transpiration, depth to groundwater, and maximum soil permeabilities for their MSWLFs can use Table 2-1

to make a reasonable assessment of the probability of obtaining a no-migration exemption. Figure 2-1 is

provided to assist owners and operators who have such information. It is a decision tool based on the data

presented in Table 2-1 . The four lettered bars in the figure show the various frequencies at which values for2

each parameter were found in successful NMDs. To use the decision tool, follow the instructions in the

footnotes to Figure 2-1. Use the following example as a further guide for understanding the instructions for

using the figure.

Example: Suppose a MSWLF receives 7 inches of precipitation annually and experiences 45 inches ofevapotranspiration annually. Suppose further that the base of the MSWLF is 225 feet above theuppermost groundwater and that the maximum permeability of the soil in the area is 3 x 10 cm/sec. The-5

owner or operator would begin by drawing a straight line between the fourth dot from the top on Bar A tothe second dot from the top on Bar B. Next, the owner or operator would draw a straight line between thefourth dot from the top of Bar C and the third dot from the top of Bar D. Finally, the owner or operatorwould connect the center points where the previously drawn lines intersect Bars F-1 and F-2. The resultwould be a fairly good probability that the MSWLF in this example would prepare a successful NMD.

Owners and operators that do not have reasonable estimates of annual precipitation, annual

evapotranspiration, depth to groundwater, and maximum soil permeabilities for their MSWLFs can collect

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such estimates inexpensively and then apply the decision tool presented in Figure 2-1. Those owners and

operators usually can obtain such values by contacting the sources of information shown in Table 2-2.

In general, information about permeability will be the most difficult to collect from the sources listed in Table

2-2. Usually, the owner or operator will receive a description of the type or types of soil that lie between the

ground surface and the uppermost aquifer -- the water table -- at the MSWLF. Each description should

include an estimate of the thickness of the soil layer being described. If the sources listed above do not

include estimates of permeabilities, but will provide soil descriptions, Table 2-3 can be used to estimate the

permeability of each soil type.

Once the permeability and thickness of each layer of soil beneath the facility have been estimated, the average

permeability can be calculated by multiplying the thickness of each soil layer by its corresponding

permeability, adding the products, and dividing that sum by the total depth to the water table.

The decision tool provides a broad screening only. Its results should not discourage the owner or operator

from continuing to pursue a NMD, unless the site appears to be at an extreme disadvantage under all criteria.

In addition, the quality of the decision made by applying the decision tool in Figure 2-1 is related directly to

the quality of the estimates for each of the four parameters. However, it is not advisable to expend significant

funds to obtain highly accurate estimates of the values for the MSWLF at this point in the screening process.

Finally, if it would require too much time or expense to find values for all the parameters in Figure 2-1, those

that would require unreasonable expenditures can be grossly estimated for the screening effort.

2.2.3 Estimation of Time of Travel

Another method of quickly and cheaply evaluating the probability that the NMD for an MSWLF will be

successful is to estimate the time required for hazardous constituents from the MSWLF to travel to the water

table. This method requires knowledge of the predominant soil type beneath the MSWLF and an estimate of

the net annual infiltration rate for precipitation at the MSWLF. Both parameters are available from the

sources listed in Table 2-2 (the U.S. Soil Conservation Service should be particularly helpful in

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TABLE 2-2: SOURCES OF SITE-SPECIFIC DATA ON KEY VARIABLES USED TO EVALUATE NO-MIGRATION DEMONSTRATIONS

Variable Sources

Depth to groundwater Water resources investigation reports at U.S. Geological Survey(USGS) regional libraries throughout the country. USGS haspublished hundreds of detailed reports of groundwaterinvestigations. The reports show well locations.

State and local geologic and natural resources and soil servicesoffices and libraries.

Soil permeability Water resources investigation reports at USGS regional librariesthroughout the country. USGS has published hundreds of detailedreports of groundwater investigations. The reports show welllocations.

State and local geologic and natural resources and soil serviceoffices and libraries.

Annual precipitation Publications of the National Climatic Data Center, of the NationalEnvironmental Satellite Data and Information Service (NESDIS),in the National Oceanographic and Atmospheric Administration(NOAA), under the U.S. Department of Commerce (DOC).

State and local meteorological and agricultural offices and services.

Local airports.

Annual evapotranspiration Publications of the National Climatic Data Center, of the NESDIS,in the NOAA, under the DOC.

State and local meteorological and agricultural offices and services

Local airports.

Infiltration Publications of the National Climatic Data Center, of the NESDIS,in the NOAA, under the DOC.

State and local meteorological and agricultural offices and services

Local airports.

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Source: Agricultural Handbook Number 456, U.S. Department of Agriculture (USDA)

The following definitions apply as used in these descriptions:1

Sand is loose and single-grained. The individual grains can be seen or felt readily. Squeezed in the hand when dry, it will fallapart when the pressure is released. Squeezed when moist, it will form a cast, but will crumble when touched.

Sandy loam is a soil containing much sand, but which has enough silt and clay to make it somewhat coherent. The individualsand grains can be seen and felt readily. Squeezed when dry, it will form a cast that will fall apart readily, but if squeezedwhen moist, will form a cast that will bear careful handling without breaking.

Silt loam is a soil having a moderate amount of the fine grades of sand and only a small amount of clay, over half of theparticles being of the size called ‘silt’. When dry, it may appear cloddy, but the lumps can be broken readily, and whenpulverized, it feels soft and floury. When wet, the soil readily runs together and puddles. Either dry or moist, it will form caststhat can be handled freely without breaking, but will give a broken appearance.

Clay loam is a fine-textured soil that usually breaks into clods or lumps that are hard when dry. When the moist soil is pinchedbetween the thumb and finger, it will form a thin ‘ribbon’ that will break readily, barely sustaining its own weight. The moistsoil is plastic and will form a cast that will bear much handling. When kneaded in the hand, it does not crumble readily buttends to work into a heavy, compact mass.

Clay is a fine textured soil that usually forms very hard lumps or clods when dry and is quite plastic and usually sticky whenwet. When the moist soil is pinched between the thumb and finger, it will form a long, flexible ‘ribbon.’ Some fine clays veryhigh in colloids are friable and lack plasticity in all conditions of moisture.

Loam is a soil having a relatively even mixture of different grades of sand and of silt and clay. It is mellow, with a somewhat

TABLE 2-3: PERMEABILITY RANGES FOR VARIOUS TYPES OF SOILS

Description (USDA Soil Class) Second (cm/sec) Feet per Year (ft/yr)1USCS Soil Class Centimeters per

2

Permeabilities 3

Sandy gravels with very little fines GW and GP (GS) > 1.0 x 10 > 10,000 -2

Silty gravels, gravel-sand-silt mixtures GM 1 x 10 to 10 1 to 1,000-6 -3

Clayey gravels, gravel-sand-clay mixtures GC 1 x 10 to 10 0.01 to 1-8 -6

Sands and gravely sands with very little SW and SP (S) > 1 x 10 > 1,000fines

-3

Silty-sands, sand-silt mixtures SM (FS, LS, LFS) 1 x 10 to 10 1 to 1,000-6 -3

Clayey sands, sand-clay mixtures SC 1 x 10 to 10 0.01 to 1-8 -6

Inorganic silts and very fine sands, rock ML (SL, FSL) 1 x 10 to 10 1 to 1,000flour, silty or clayey fine sands, clayey siltswith slight plasticity

-6 -3

Inorganic clays of low to medium CL (L, SIL) 1 x 10 to 10 0.01 to 100plasticity, gravelly clays, sandy clays, siltyclays, lean clays

-8 -4

Organic silts and organic silt-clays of low OL 1 x 10 to 10 1 to 100plasticity

-6 -4

Inorganic silts, micaceous or MH 1 x 10 to 10 1 to 100diatomaceous fine sandy or silty soils,elastic silts

-6 -4

Inorganic clays of high plasticity, fat clays CH 1 x 10 to 10 0.01 to 1-8 -6

Organic clays of medium to high OH 1 x 10 to 10 0.01 to 1plasticity, organic silts

-8 -6

14

gritty feel, yet fairly smooth and slightly plastic. Squeezed when dry, it will form a cast that will bear careful handling, whilethe cast formed by squeezing the moist soil can be handled quite freely without breaking.

The Unified Soil Classification System (USCS) is one of two nationally recognized and widely used systems for estimating soil2

properties. The other is the USDA scale, which also is based on the soil texture and the various percentages of sand, silt, andclay. Therefore, the descriptions of a soil’s texture can be used to classify it under either system and to convert from onesystem to another.

To convert cm/sec to ft/yr multiply by 1,034,645.6. Thus, 1 x 10 cm/sec equals approximately 1 ft/yr.3 -6

obtaining the information). When the net infiltration rate and the predominant soil textures at the MSWLF

are known, Table 2-4 can be used to estimate the minimum depth to groundwater necessary for a no-

migration exemption at an MSWLF that will operate for 30 years and undergo post-closure care for an

additional 30 years. It should be noted that the permeability of many clays is well below 17 feet per year,

therefore the use of Table 2-4 will yield conservative results at many sites where clays are the predominant

soil type (The method used to construct the table is based on equations taken from the Superfund Site

Assessment Manual [EPA 1988]).

When the net infiltration rate is not known, but the predominant soil texture is known, conservative estimates

can be used to estimate the minimum depth to groundwater necessary for a no-migration exemption at an

MSWLF that will operate for 30 years and undergo post-closure care for an additional 30 years. These

estimates of minimum depths are 120 feet for sand; 78 feet for sandy loam; 60 feet for silt loam; 48 feet for

clay loam; and 24 feet for clay.

The estimates were derived by assuming an annual average precipitation rate of 25 inches per year, minus

values for surface runoff and evapotranspiration rates taken from Table C-8 in Hydrologic Simulation on

Solid Waste Disposal Sites, Office of Water and Waste Management, EPA (SW-868), September, 1980.

If you know your average annual precipitation rate and you are in a relatively dry area, you can assume that

only 15 percent of the average annual precipitation will infiltrate. That assumption represents conservative

values of 15 percent runoff and 70 percent evapotranspiration rates.

2.3 CONTENT OF A NMD

The previous sections of this chapter described how to apply limited and inexpensively gathered information

to determine whether a NMD can be expected to be successful. This section suggests the

specific types and amounts of information that state officials will expect to see before making a decision

about a no-migration exemption. Officials typically responsible for such matters include individuals

15

This table was adapted from instruction for calculating the velocity of infiltrating rainwater in the Superfund Exposure1

Assessment Manual, Office of Emergency and Remedial Response, EPA (EPA/540/1-88/011). It is intended for use as ageneral tool, and should not be applied to MSWLFs that are located over poorly-sorted sand, gravel, fractured rock, or karstterrains.You can obtain net infiltration or percolation rates for your area by contacting the local offices of the U.S. Soil Conservation2

Service or your state geological survey office. The rate is equal to the total annual average precipitation rate, minus losses ofmoisture through runoff and evapotranspiration. Note that these permeabilities are higher than those measured in many clayey soils; therefore, they contribute to a conservative3

estimate of velocities at sites that have clayey soils.

TABLE 2-4: MATRIX FOR GROSS ESTIMATING OF THE VELOCITY OF MIGRATION

OF HAZARDOUS CONSTITUENTS TO THE WATER TABLE1

Average Annual Net

Infiltration or Percolation

Rate2

Soil Texture Water Table for a

(Permeability Value MSWLF With a 60-year

Used in Calculating Estimated Velocity of Total Operating Life and

Velocity in Feet per Contaminant Migration Post-Closure Care Period Inches per Feet per

Year) (Feet per Year) (Feet)Year Year 3 4

Minimum Depth to the

1 0.0834 0.6 36

Sand (6,000)10 0.834 4.7 282

5 0.417 2.5 150

15 1.25 6.8 408

20 1.67 8.8 529

1 0.0834 0.4 24

Sandy loam (745)10 0.834 3.3 198

5 0.417 1.7 102

15 1.25 4.8 288

20 1.67 6.2 372

1 0.0834 0.3 18

Silt loam (196)10 .834 2.6 156

5 0.417 1.3 80

15 1.25 3.7 222

20 1.67 4.9 294

1 0.0834 0.2 12

Clay loam (66)

5 0.417 1.1 66

10 0.834 2.2 132

15 1.25 3.2 192

20 1.67 4.2 253

1 0.0834 0.2 12

Clay (17.5)10 0.834 1.9 114

5 0.417 1 60

15 1.25 2.9 174

20 1.67 3.8 228

16

Calculations of velocities of migration of contaminants were based on the following formula:4

V = q /p

where:

q = Average percolation or recharge rate (depth per unit time)p = Volumetric moisture content of the unsaturated zone (decimal fraction representing volume of water per volume of soil)

The values used to represent "p" above were specific for each soil texture shown in the table and originally were derivedthrough laboratory tests on numerous soils having those textures, as reported in the Superfund Exposure Assessment Manual.

having such titles as solid waste engineer, solid waste management official, or director of a solid waste

permit section. To contact such officials, call the headquarters of the state department of environmental

protection and ask for the office of solid waste. Make an appointment to visit with an official of that office.

Ask whether the state has specific guidance for NMDs or any written decision criteria that can be obtained

before the meeting. Explain to the state official the need to know exactly what types of data must be

submitted. For example, Table 2-5 is a data collection form for keeping track of the information needed for

the NMD. It is important that the information recorded be as complete and accurate as possible because that

information will be used to estimate the probable total costs of preparing the NMD. Be prepared to answer

questions about the MSWLF. In addition, inform the official of the location and design of the MSWLF and

its waste acceptance rate. Ask which characteristics of the MSWLF would increase or decrease the

probability that it will receive a no-migration exemption.

During the meeting with the state official, verify that all the written guidance and forms necessary to complete

the NMD have been provided. Review each type of data listed in Table 2-5 and ask whether it is required. If

a particular type of data is required, ask whether the information must be determined from on-site

measurements or whether the results of similar measurements taken at nearby facilities are sufficient. As an

alternative, ask whether values in the literature that describe the general hydrogeologic setting in the area can

be used in place of on-site measurements for certain items. Ask for recommendations of any specific

literature that provides values for particular data elements. For data that must be collected on a site-specific

basis, ask whether there is a minimum number of samples that must be collected. In addition, ask whether

there is a minimum number of borings that must be drilled to collect data on certain parameters and how deep

the borings must be.

Be certain to ask the state official whether there are any types of data that are not listed in Table 2-5 that must

be included in the NMD. List the additional items in the blank spaces in the table, and complete all columns

of the table for those items, just as the other items in the table.

17

TABLE 2-5: NMD DATA COLLECTION FORM(Page 1 of 2)

Types of Data (Y/N/M) Measurement Testing

InformationRequired? Sources of Information Not Requiring Numbers and Methodologies for Required On-Site

1 2 3

Depth to groundwater

Soil permeability(hydraulicconductivity)

Soil porosity

Bulk density of soil

Moisture content ofsoil

Moisture content ofwaste

Soil moisture at fieldcapacity

Soil moisture at thewilting point

Soil classification/soiltexture

Models (list type[s])

Maximum depth ofMSWLF

Average annualprecipitation

Average runoff rate

18

TABLE 2-5: NMD DATA COLLECTION FORM(Page 2 of 2)

Types of Data (Y/N/M) Measurement Testing

InformationRequired? Sources of Information Not Requiring Numbers and Methodologies for Required On-Site

2 3

Infiltration orpercolation rate

Average annualevapotranspiration rate

Thickness of liner(each material)

Permeability of liner(each material)

Thickness of cover(each layer)

Permeability of cover

Notes:

1 Y = YesN = NoM = Maybe, because the state appears to be strongly recommending this type of data.

2 Ask the state official about sources of data for those data requirements that can be satisfied with data from previous studies of the soils or climate in the area of the MSWLF. Ask whether there is a maximum distance from the MSWLF beyond which the state will not allow the use of data from the literature.

3 Ask the state official about the types of testing that must be performed directly at the MSWLF. If any such testing already has been performed, ask the official whether theresults are adequate to meet the state’s requirements without additional testing.

19

Finally, ask the state official which, if any, hydrogeological models must be run to demonstrate the migration

rates of hazardous materials from the MSWLF. Ask whether the state will run such models and whether

officials can use default values to make a decision about the MSWLF without requiring the submittal of a

NMD. Determine whether the state has predesignated certain portions of the state as good or poor locations

for candidates for no-migration exemptions.

After Table 2-5 has been completed, the next step is to develop a ballpark estimate of the costs of completing

a NMD for the MSWLF. The next chapter of this manual is a guide to completing that task.

20

3.0 STEP 2: ESTIMATE AND ANALYZE THE COST OF THE NMD

This chapter includes two sections. Section 3.1 presents an approach to determining a ballpark estimate of

the costs of preparing a NMD. Section 3.2 presents an approach to determining whether the preparation of a

demonstration is cost-effective in any particular case.

3.1 ESTIMATE THE COST OF A NMD

Using the data collection form filled out as described in Section 2.3 (see Table 2-5), identify the information

that already has been collected. For example, much of the information needed might be found in the permit

application for the MSWLF. Next, identify the information listed on the data collection form (Table 2-5) that

the state will allow to be obtained from literature. In many cases, an owner or operator can obtain literature

free or for a nominal fee from local, state, and federal government sources and from universities. Assume

that the cost of obtaining each source of information is $150.00, except for information that obviously will

require little time to collect. (The figure of $150.00 is based on the assumption that it would require

approximately four hours of a junior consultant's time, and $50.00 in other direct costs, to retrieve

information from each literature source.) Some of the information needed for a particular site may not be

available in the literature; therefore, it may be necessary to revise the cost estimate after a review of

information from the various sources suggested by the state solid waste official.

After entering the information from literature on the data collection form, review the types of information

listed on the form that must be collected at the MSWLF through sampling. Use Table 3-1 to prepare a

ballpark estimate of the cost of each such item. If items required by the state are not listed in Table 3-1,

obtain estimated unit prices from local soil laboratories, local drillers, consulting firms, state officials,

universities, or owners or operators of nearby MSWLFs where such testing has been performed. The

estimate will be much more accurate if such contacts provide information to support the estimates of the costs

of all the items listed in Table 2-5. However, the rates listed in Table 3-1 can be used to construct a quick

ballpark estimate before making telephone calls to refine the unit costs upon which the estimate would be

based.

21

TABLE 3-1: RATES FOR COSTING VARIOUS ON-SITE MEASUREMENTSTHAT MAY BE REQUIRED BY THE STATE (1996)

(Page 1 of 2)

Types of Data Procedure Unit Cost Number Required Total Cost1

Depth to groundwater Drilled boring $30/foot2

Soil permeability Laboratory $100/test(hydraulic conductivity) test

Soil porosity Laboratory $25/testtest

Bulk density of soil Laboratory $25/testtest

Moisture content of soil Laboratory $25/testtest

Moisture content of waste Laboratory $25/testtest

Soil moisture at field Laboratory $25/testcapacity test

Soil moisture at the wilting Laboratory $25/testpoint test

Soil classification/soil Laboratory $25/testtexture test

Models (list type[s]) Computer $2,000/ 1 $2,000analysis analysis3

Maximum depth of Drilled boring $20/footMSWLF

4

Average annual NA NA NA NAprecipitation

Average runoff rate Field $100measurement

Infiltration or percolation Field $100rate measurement

Average annual NA NA NA NAevapotranspiration rate

Thickness of liner (each Drilled boring $20/footmaterial)5

6

Permeability of liner (each Laboratory $100/Testmaterial) analysis

Thickness of cover (each Hand augering $500layer)

22

The number of measurements needed for each data type often is expressed in terms of the depths of the borings to be made. 1

Therefore, it is important to consider both the total depth and the number of borings when estimating the total number of eachtest to be conducted at your MSWLF.This unit cost is based on the assumption that the boring will be six inches in diameter, will exceed 100 feet in depth, and will2

be drilled with an air rotary drill by a three-man crew consisting of one operator and two unskilled laborers, and that the boringwill be cased, capped, and fitted with a concrete pad. The diameter of six inches is recommended for borings done at your sitebecause such borings can be converted into groundwater monitoring wells if the NMD is not successful. The added cost ofthat approach is approximately $10 per foot.Assumes that data already have been collected and are available to the modeler. Also assumes 24 hours of a junior modeler's3

time and 8 hours of a senior modeler's time, plus materials.The diameter of the boring is assumed to be two inches.4

It is not likely that many states will require this test because it could jeopardize the integrity of the containment structures of5

the MSWLF.The diameter of this boring is assumed to be two inches.6

TABLE 3-1: RATES FOR COSTING VARIOUS ON-SITE MEASUREMENTSTHAT MAY BE REQUIRED BY THE STATE

(Page 2 of 2)

Types of Data Procedure Unit Cost Number Required Total Cost

Permeability of cover Laboratory $100/testanalysis

TOTAL COSTS NA NA NA

Notes:

NA = Not Applicable

After completing Table 3-1, add the costs and record the total at the bottom of the right-hand column. Add

that figure to the total cost estimated for collection of the information that can be obtained from the literature.

Add to the new total $5,000 to retain a consultant to communicate with the state, analyze information about

your site, and prepare the NMD. In most cases, the consultant should be able to perform those tasks for less

than that amount; however, a ballpark estimate should err on the high side rather than the low.

The total cost of groundwater monitoring calculated as described above should be compared with the

estimated cost of preparing a NMD. In many cases, preparing a NMD costs far less than groundwater

monitoring.

3.2 ANALYZE THE COST OF THE NMD

A method of analysis is to compare the cost of a NMD to the cost of groundwater monitoring. Once a

reasonable estimate of the costs of the NMD has been prepared, compare that amount with the cost of

installing a groundwater monitoring system and monitoring the groundwater over the active life of the

23

EXAMPLE COST ESTIMATE FOR A GROUNDWATER MONITORING SYSTEM

Installation : $90/feet/well x 200 feet x 3 wells = $54,0001

Monitoring : $1,800/well x 3 wells = $5,4002

Monitoring : $600/well/year x 3 wells x 19 years + I = $41,9353

Post-closure : $600/well/year x 3 wells x 30 years + I = $108,5004

TOTAL $209,835

1 1998 dollars.2 First year of the remaining life of the landfill (1998 dollars).3 Second through twentieth year of the remaining life of the landfill; I = inflation of 2 percent per year.4 Monitoring for thirty years after the end of the remaining life of the landfill; I = inflation of 2 percent peryear.

MSWLF, plus the post-closure care period. To estimate the cost of installing a groundwater monitoring system:

C Multiply $90 by the depth to groundwater at the site (in feet), and multiply the result by thenumber of wells that are likely to be needed. (A state solid waste official will be able toprovide an estimate of the number of groundwater monitoring wells that may be needed at agiven MSWLF.)

C Add to that number $600 per well per year for 30 years of post-closure care at the MSWLF.

C For monitoring in the first year, add $1,800 per well

C For all annual monitoring conducted after the first year, add $600 per well for eachremaining year of operation of the MSWLF.

For example, groundwater

monitoring at a facility that has

three, 200-foot-deep wells and 20

years of remaining active life

would cost a total of $209,835

(see text box for details on this

example). In addition, at least 60

hours of consulting time would be

needed for well design and

placement and oversight, estimated at approximately $5,000, bringing the total costs of groundwater

monitoring for the facility to $214,835. The cost of a NMD for the same facility could be expected to be

approximately $15,000, assuming that only one boring is required and that all soil tests would be repeated at

20-foot intervals. That cost should be reduced by the cost of the boring (approximately $30/foot times 200

feet or $6,000), because the boring can be used to install a groundwater monitoring well should the NMD be

unsuccessful. Therefore, for a MSWLF that meets the description above, a NMD can be prepared for an

incremental cost of approximately $9,000, or about four percent of the cost of installing and operating a

groundwater monitoring system. Such differences between the costs of groundwater monitoring and those of

preparing a NMD are expected to be common to most, if not all, MSWLFs. In addition, the approach

described in the following chapter allows the owner or operator to recognize at the earliest possible point that

a NMD is likely to be unsuccessful, so that the effort can be abandoned before large expenditures of time and

effort are made.

24

4.0 STEP 3: FOLLOW COST-EFFECTIVE METHODS OF PREPARING THE NMD

The following four steps are the most cost-effective approach to preparing a NMD:

C Prepare a clear written description of needs and discuss those needs with state solid wasteofficials

C Discuss the needs with consulting firms that specialize in the field

C Using standard practices, select a consultant

C If state does analysis, no consultant needed

The four steps are discussed in the following subsections.

4.1 PREPARE A CLEAR WRITTEN DESCRIPTION OF NEEDS

This step was completed substantially during the visit with the state solid waste official. However, it is

important to document all the information that will be needed for a NMD in a one- or two-page description

supported by a table similar to Table 2-5. Once that description has been prepared, it may become apparent

that there are some areas of uncertainty concerning the number or types of tests that must be reported in the

NMD. However, even if there are no information gaps in the description, an attempt should be made to

obtain comments from state officials on the information required in a NMD. In addition, attempt to obtain

comments from those state officials on the types of information that will be crucial to their decision and the

types of information that almost certainly will cause the rejection of a NMD. Explain that the rationale for

asking such questions is to limit expenditures for consultants to complete the NMD by terminating the

preparation of the NMD at the earliest indication that it will not succeed. Use the results of the discussions

with state officials to determine whether to engage a consultant to prepare the NMD. Some states may have

in place formal or informal procedures for analyzing information about MSWLFs in such a way that only the

raw data on an MSWLF must be presented to them. In those states, a consultant might not be needed to

prepare the demonstration. However, use of a consultant to oversee the collection of any field data required

by the state is recommended.

4.2 DISCUSS NEEDS WITH CONSULTING FIRMS

Contact three or more consulting firms that specialize in hydrogeological evaluations. Such firms are listed in

local telephone directories. Recommendations of competent firms can also be obtained from other owners or

25

operators of MSWLFs. Call each firm and ask to speak with a senior hydrogeologist. Explain to that person

that you are considering submittal of a NMD for a MSWLF, and ask to speak with the appropriate person in

the company. Describe to that person pertinent facts about the MSWLF -- its size, the depth to groundwater,

and the climate -- and explain the information needs identified in cooperation with state officials. Agree to

provide the firm with an invitation to bid on the preparation of the NMD, if the firm is interested. Ask each

firm about its experience in preparing such demonstrations, and encourage the contact to offer an opinion

about the probability that the NMD will be successful. Ask each contact to comment on whether the

information about data needs identified appear to be complete and accurate, in light of the firm's experience.

Discuss any major discrepancies related to information needs with state officials. Ask them to reconfirm the

need for information that one or more consulting firms believed to be unnecessary, or to reconfirm that there

is no need for information that one or more consulting firms believed to be crucial.

4.3 SELECT A CONSULTANT

Prepare an invitation for bid for three or more consulting firms believed to be reputable, in light of the

recommendations of past clients and the opinion formed during telephone conversations with their staffs.

The invitation for bid should state clearly exactly what is expected of the contractor in preparing the NMD. It

is recommended that each contractor be required to provide a brief summary of the experience of its staff and

its company in preparing such demonstrations, both successful and unsuccessful. In lieu of such experience,

a contractor should explain how the experiences of its staff and its company are relevant to the preparation of

a successful NMD. In addition, the bid package should request that each contractor describe specific criteria

that could be used to trigger the abandonment of the NMD at any of a number of stages in the preparation

process. Such a step-by-step approach could reduce the cost of preparation of a NMD by allowing the owner

or operator to cease such efforts if success begins to appear unlikely. For example, a company may propose

to conduct a visual evaluation of coring samples from borings at the site and make a decision about whether

to proceed with the preparation of the demonstration. Such interim evaluations could produce significant

savings at sites for which more than one boring or numerous laboratory tests on soil samples are needed to

support a NMD. At the very least, each firm should be asked to provide a subtotal of costs for collection and

presentation of all required information, with a preliminary conclusion about the probability that a NMD

would be successful. Such an approach could save the cost of preparing a demonstration in cases in which

there is very little probability of success.

The instructions in the bid package should state clearly how the firm awarded the contract will be selected.

For example, the owner or operator may elect to use three criteria, such as experience, approach, and total

26

cost, in evaluating the bids. In such a case, each of the bidders would be rated on a scale of 1 to 10 for its

responses to each of the evaluation criteria. For example, a total cost that is twice the amount of the lowest

offer might receive a rating of 2 and a bidder that proposes three or more decision points that collectively

have the potential to save 50 percent of the total estimated cost of the project might receive a rating of at least

8. Next, the score of each bidder under each criterion would be multiplied by a weighing factor that

represents the relative importance of that criterion in the evaluation. Finally, the results in each category

would be added to obtain a total score for each bidder. The bidder having the highest score should be selected

for negotiations to encourage the bidder to reduce its costs or increase its proposed activities. In all cases, it

is important to maintain control over the evaluation process, so that no bidder is selected if none meets the

requirements.

Appendix

Information Used to Analyze

No-Migration Demonstrations

in Seven States

A-i

TABLE OF CONTENTS

Table Page

A-1 CRITERIA USED BY STATES TO MAKE DETERMINATIONS

ABOUT NO-MIGRATION EXEMPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

A-2 VALUES FOUND FOR KEY PARAMETERS IN SUCCESSFUL

NO-MIGRATION DEMONSTRATIONS MSWLFS IN ARIZONA . . . . . . . . . . . . . A-4

A-3 COMPARISON OF PARAMETERS AND VALUES USED BY EACH STATE . . A-11

Arizona Department of Environmental Quality (ADEQ) recommends the use of Hydrologic1

Evaluation of Landfill Performance (HELP) and MULTIMED models with site-specific data tosatisfy the requirements of 40 CFR 258.50(b)(1)&(2). Arizona does not use the form displayed inTable 2-5.

A-1

Table A-1

CRITERIA USED BY STATES TO MAKE DETERMINATIONS ABOUT NO-MIGRATION EXEMPTIONS

(Page 1 of 3)

State Regulatory Criteria Used to Make Determination References

Arizona 40 CFR 258.50(b)(1)(2)3 Exemption from groundwater monitoring requirements• Demonstration that there is no potential for migration of

hazardous constituents from that MSWLF to the uppermost aquifer- Measurements collected at specific field sites and sampling and

analysis of physical, chemical, and biological processes affecting thefate and transportation of contaminants

- Predictions of the fate and transport of contaminants that maximizemigration of contaminants and a consideration of the effects onpublic health and safety and the environment

• Certification by a qualified groundwater scientist• Approval by the director of the Department of Environmental Quality

Idaho Solid Waste Facilities Act,Exemption from groundwater monitoring requirements• Demonstration that there is no potential for migration of hazardous Title 39, Chapter 7410

constituents from the landfill to the uppermost aquifer during the activelife of the unit and the post-closure care period

• Certification by a qualified groundwater scientist• Approval by the director of the Idaho Environmental Council

Montana Solid Waste Management,Exemption from groundwater monitoring requirements• Demonstration that there is no potential that hazardous constituents will Subchapter 7,

contaminate the uppermost aquifer 16.14.714(1)(2)(3)(5) (p.• Provision of facility-specific data and studies certified by a qualified 16-793)

groundwater scientist- Site-specific, field-collected measurements, sampling, and analysis of

physical, chemical, and biological processes affecting contaminantfate and transport

- Predictions of contaminant fate and transport that maximizemigration of contaminant and consider effects on human health andthe environment

• Demonstration that groundwater will not become contaminated for atleast 30 years after the facility is closed

• Installation of vadose zone monitoring devices, piezometers, or saturatedzone monitor wells as required by the department as part of an ongoingno-migration demonstration

TABLE A-1CRITERIA USED BY STATES TO MAKE DETERMINATIONS ABOUT NO-MIGRATION EXEMPTIONS

(Page 2 of 3)


A-2

Nevada Solid Waste Disposal,Exemption from groundwater monitoring requirements• Demonstration that there is no potential for migration of hazardous General Provisions,

constituents from that unit to the uppermost aquifer during the active life 444.7481(a)(b) of the unit, including the period of closure and post-closure care period (p.444-116)- Site-specific measurements and the sampling and analysis of

physical, chemical, and biological processes affecting the fate andtransport of contaminants

- Predictions of the fate and transport of contaminants that are basedon the maximum possible rate of migration of the contaminant andconsideration of the effects on public health and safety and theenvironment

• Certification by a qualified groundwater scientist• Approval by the solid waste management authority

New Solid Waste ManagementMexico Regulations, Part VIII,

Exemption from part or all of groundwater monitoring requirementsunder Sections 802 to 806• Demonstration that there is no potential for migration of hazardous 801.C.1.2 (p. 103)

constituents from the landfill to the uppermost aquifer during the activelife and the post-closure care period- Site-specific field measurements and sampling and analysis of

physical, chemical, and biological processes affecting fate andtransport of contaminant(s)

- Predictions of the fate and transport of the contaminant(s) thatmaximize migration of the contaminant(s) and consideration of theeffects on public health and welfare and the environment

• Certification by a qualified groundwater scientist• Approval by the secretary of the Department of the Environment

Utah Solid Waste PermittingExemption from groundwater monitoring requirements• Demonstration that there is no potential for migration of hazardous and Management Rules,

substances from the facility to the groundwater during the active life of R315-308-1(3)(a)(b)the facility and the post-closure care period (p. 22)- Site-specific, field-collected measurements and sampling and analysis

of physical, chemical, and biological processes affecting fate andtransport of the contaminant(s)

- Predictions of the fate and transport of the contaminant(s) thatmaximize migration of the contaminant(s) and consideration of theeffects on human health and the environment

• Certification by a qualified groundwater scientist• Approval by the Executive Secretary of the Department of

Environmental Quality

Exemption from some design criteria and groundwater monitoringrequirements (new or existing facilities that are seeking expansions)• Requirement that the MSWLF be located over an area where

- Groundwater has total dissolved solids (TDS) of 10,000 milligramsper liter (mg/L) or higher

- There is extreme depth to groundwater- There is a natural impermeable barrier over groundwater- There is no groundwater

R315-302-1(2)(vi)

TABLE A-1CRITERIA USED BY STATES TO MAKE DETERMINATIONS ABOUT NO-MIGRATION EXEMPTIONS

(Page 3 of 3)


A-3

Wyoming Solid Waste RulesExemption from groundwater monitoring requirements,Type I landfill• Demonstration that there is no potential for migration of hazardous

constituents from the facility to the uppermost aquifer- Site-specific field measurements- Information about the specific wastes to be disposed of at the facility- Predictions of fate and transport of contaminants, including use of

the hydrologic evaluation of landfill performance model, thatmaximize migration of contaminants and consider effects on humanhealth and the environment

Type II landfill• Groundwater monitoring systems are not automatically required for

Type II landfills, but may be required after the department reviews thepermit application

and RegulationsChapter 2, Section 6(b)(I)(A)(I), (P2-32)

A-4

TABLE A-2: VALUES FOUND FOR KEY PARAMETERS IN SUCCESSFUL NO-MIGRATION DEMONSTRATIONS FOR SPECIFIC MSWLFS IN ARIZONA1

(Page 1 of 7)

Name of Disposal Rate Active Life of Facility Thickness and Permeability Groundwater of Soil or Hydraulic Annual Precipi- Evapotranspiration DemonstrationFacility (tons/day) (yr) of Daily Cover (ft) Conductivity tation Rate (in) Rate (in) Models Used ($)

Size (acres) and Depth to Average Permeability Annual PrepareCost To

Cerbat 160; NI 30 - 40 6 in; compacted cover 18 - 160 Silty and gravelly sand; 10 76 HELP, vers. NImaterial 1.23x10 cm/sec* 2.05, 4,100 to 5,000**-3

(sandy loam) WHPA, vers.2.0(RESSQC)***

Note:

The term "key" as used here reflects professional judgement concerning those items that may have been most crucial to the state in granting no-migration exemptions. (1)

NI Information not included

* Typical hydraulic conductivity for a sandy loam was used for the Hydrologic Evaluation of Landfill Performance (HELP) program.** The cost to produce the demonstration is unclear. Modeling was being done for various reasons when it was decided to apply for a no-migration exemtion. At that point, substantial information was available to be included in the

demonstration, thereby keeping the cost to a minimum.*** Trademark model names.

A-5

TABLE A-2: VALUES FOUND FOR KEY PARAMETERS IN SUCCESSFUL NO-MIGRATION DEMONSTRATIONS FOR SPECIFIC MSWLFS IN IDAHO1

(Page 2 of 7)

Name of Disposal Rate Active Life of Thickness and Permeability of Groundwater Soil or Hydraulic Precipitation Annual Evapotranspi- DemonstrationFacility (tons/day) Facility (yr) Daily Cover (ft) Conductivity Rate (in) ration Rate (in) Models Used ($)

Size (acres) and Depth to Average Permeability of Annual Cost To Prepare

Clay Peak 120; 44.45 68 6 in; fine-grained soil 297.9 to 334.9 1.4 x 10 to 4.2 x 10 10.21 59.85 HELP, approx. 240K-4 -4

cm/sec; CHEMFLO,1.1 x 10 to 4.0 x 10 MULTIMED-5 -18

cm/sec; 1.7 to 3 inches perfoot of soil

Lemhi County 16.5; NI > 40 6 in; any soil type > 325 Clay with high plasticity; 9.39 30 HELP ver. 2.0, 84K*Landfill 1.8 x 10 to 3.6 x 10 CHEMFLO,-9 -9

cm/sec SUTRA

Pickles Butte 370; NI > 200 6 in; fine-grained soil > 400 NI; 6-8 50 HELP 25K to 30K1.0 x 10 to 1.8 x 10-4 -9

cm/sec

Note:



* This number is a factor in the cost of a no-migration demonstration. The cost actually incorporates overall design of the landfill, as well as design of the collection system.

A-6

TABLE A-2: VALUES FOUND FOR KEY PARAMETERS IN SUCCESSFUL NO-MIGRATION DEMONSTRATIONS FOR SPECIFIC MSWLFS IN MONTANA1

(Page 3 of 7)

Name Disposal Rate Active Life of Permeability of Daily Groundwater of Soil or Hydraulic Annual Precipi- Annual Evapotranspi- Demonstrationof Facility (tons/day) Facility (yr) Cover (ft) Conductivity tation Rate (in) ration Rate (in) Models Used ($)

Size (acres) and Thickness and Depth to Average Permeability Cost To Prepare

Former Laurel NI; NI NI NI; NI 6 - 30 Vertical mitigation rate of 14 45 Not used 25KSanitary Landfill (closed in 1995) (In accordance with gw: 0.2 - 2.3 ft/yr; 8.11 x(License No. 203) Subtitle D Regs.) 10 cm/sec-8

Chester Landfill 48; 1.7 70 6 in to 1 ft; NI 200 to 250 NI; NI 10.64 NI Not used NI

Coral Creek Landfill 70; 9 28 6 in; NI avg. 300 Tight soils approx. 14 NI Not used *5K + 2yrs.permeability = 10 or 10-6 -

cm/sec; NI7

Existing Landfill (Big 76; NI NI 6 in; NI 60 9.5 x 10 cm/sec; NI 12.3 NI Not used 4565.45Horn County and Cityof Hardin)

-8

Valley County 40; NI 73 6 in; NI 50 5.1 - 9.6 x 10 cm/sec; 11 NI Not used 18K initial study;Landfill 4.63 x 10 cm/sec $9,935-secondary

-8

-7

study & no-mig.recommended

Beaverhead County < 100; NI 74 approx 6 in; NI > 350 1 x 10 to 9.53 48 Not used 8K to 9K-5

1 x 10 cm/sec;-4

1 x 10 cm/sec-4

Note:



* $5,000 was spent on the engineering portion; however, two or more unrecorded years of personal time were expended on the project.

A-7

TABLE A-2: VALUES FOUND FOR KEY PARAMETERS IN SUCCESSFUL NO-MIGRATION DEMONSTRATIONS FOR SPECIFIC MSWLFS IN NEVADA1

(Page 4 of 7)

Name of Facility (tons/day) Facility (yr) Cover Groundwater (ft) Hydraulic Conductivity tation Rate (in) Rate (in) Models Used ($)

Size (acres) and Thickness and Annual PrepareDisposal Rate Active Life of Permeability of Daily Depth to Average Permeability of Soil or Annual Precipi- Evapotranspi-ration Demonstration

Cost To

City of Mesquite 40; NI NI > 6 in; compacted cover > 400 1 x 10 cm/sec (silt & clay) and 1 4.1 NI HELP II, vers. NIMunicipal Waste material x 10 - 1 x 10 cm/sec (fine 2.5Landfill sands); NI

-8

-3 -4

Note:



A-8

TABLE A-2: VALUES FOUND FOR KEY PARAMETERS IN SUCCESSFUL NO-MIGRATION DEMONSTRATIONS FOR SPECIFIC MSWLFS IN NEW MEXICO1

(Page 5 of 7)

Name of Facility Rate (tons/day) Facility (yr) Cover (ft) Conductivity Rate (in) ration Rate (in) Models Used ($)Size (acres) and Disposal Active Life of Permeability of Daily Groundwater of Soil or Hydraulic Precipitation Annual Evapotranspi- Demonstration

Thickness and Depth to Average Permeability Annual PrepareCost To

Corralitos Landfill 480 (East phase: 200 20 (East phase) 6 in; NI > 430 1.0 x 10 cm/sec; NI 9.56 93.95 HELP 10K and publicacres); 350 hearing costs

-4

Note:



A-9

TABLE A-2: VALUES FOUND FOR KEY PARAMETERS IN SUCCESSFUL NO-MIGRATION DEMONSTRATIONS FOR SPECIFIC MSWLFS IN UTAH1

(Page 6 of 7)

Name of Disposal Rate Active Life of Facility Permeability of Daily Depth to Groundwater of Soil or Hydraulic Annual Precipi- Annual Evapotranspi- Models DemonstrationFacility (tons/day) (yr) Cover (ft) Conductivity tation Rate (in) ration Rate (in) Used ($)

Size (acres) and Thickness and Average Permeability PrepareCost To

Millard County 80; 20-25 200 6 in; compacted cover 35 - 80 6 x 10 to 6 to > 25 60 HELP II, 18KLandfill material 1 x 10 cm/sec; NI vers, 2.05

* -9

-8

WHPA

Long Hollow NI; NI 20+ 6 in; 3 x 10 cm/sec > 300 1.9 x 10 cm/sec; NI < 10 50 HELP NISanitaryLandfill

-3 -6

Note:



* The active life of facility is estimated from the information about the size of the facility (80 acres) and the size (0.8 acre) and active life (two years) of each cell.

A-10

TABLE A-2: VALUES FOUND FOR KEY PARAMETERS IN SUCCESSFUL NO-MIGRATION DEMONSTRATIONS FOR SPECIFIC MSWLFS IN WYOMING1

(Page 7 of 7)

Name of Facility (tons/day) (yr) Cover (ft) Conductivity Rate (in) (in) Models Used ($)

Size (acres) and Thickness and Average Permeability Annual Evapotranspi- PrepareDisposal Rate Active Life of Facility Permeability of Daily Depth to Groundwater of Soil or Hydraulic Precipitation ration Rate Demonstration

Annual Cost To

Green River #1 40 ; 47.5 10 6 in; sandy, rocky loam > 130 (no gw 5 x 10 to < 1 x 10 4-8 37 NI NILandfill encountered) cm/sec

2 3

4

-3 -6 5 *

Rock Springs Sanitary 47; 273 4 6 in; compacted earth 52 to >100 2 x 10 to NI NI NI NI#1 Landfill 2 x 10 cm/sec

6 7 -4

-6

*

Sublette County 40; 52 15 6 in; NI 80 6 x 10 cm/sec 15 NI NI NIMarbleton Sanitary #2Landfill

8 8 -8 *

Note:

* Exemptions from groundwater monitoring requirements were granted during permit renewal processes. Therefore, it appears that it did not cost the landfill owner a separate amount to apply for a no-migration demonstration.The term "key" as used here reflects professional judgement concerning those items that may have been most crucial to the state in granting no-migration exemptions. (1)

40 acres indicate expansion of the landfill after closure of a 55-acre site. (2)

47.5 tons per day were estimated, from the annual disposal rate, 12,350 tons per year (260 operating days per year). (3)

Groundwater monitoring is not required, because there is no groundwater up to a depth of 130 feet. (4)

The state permit application review file indicates that the HELP model was used primarily for the waiver of the requirement for an engineering containment system. (5)

273 tons per day were estimated from the estimated monthly disposal rate, 6,550 cubic yards per month, assuming 24 days (Monday through Saturday working days at the landfill) per month. (6)

According to site-specific geology and poor water quality data, groundwater monitoring is not required. However, as an alternative, lysimeters have been installed at this site to measure fluid content of the substrata. (7)

The daily disposal rate was calculated from the annual disposal rate of 19,000 tons per year, assuming seven working days per week. (8)

No groundwater was detected during the drilling operation. The depth to groundwater, 80 feet, was obtained from information about domestic wells from the state engineer’s office. (9)

A-11

TABLE A-3: COMPARISON OF PARAMETERS AND VALUES USED BY EACH STATE

KEY PARAMETERS AND RANGE VALUES(1)

Name of Size (acres) and Disposal Active Life of Permeability of Daily Groundwater Soil or Hydraulic Annual Precipi- Annual Evapotranspi- Cost To PrepareFacility Rate (tons/day) Facility (yr) Cover (ft) Conductivity tation Rate (in) ration Rate (in) Models Used Demonstration ($)

Thickness and Depth to Average Permeability of

Arizona* 160; NI 30 - 40 6 in; compacted cover 18 - 160 Silty and gravelly sand; 10 76 HELP, vers. NImaterial (>120) 1.23x10 cm/sec* (sandy 2.05, 4.1K to 5K-3

loam) WHPA, vers. 2.0(RESSQC)

Idaho 16.5 to 370; 44.45 >40 to >200 6 in; any soil type and 297.9 to >400 1.4 x10 to 4.2 x10 cm/sec 6 to 10.21 30 to 59.85 HELP, 25K to 240Kfine grained soil and clay w/high plasticity; CHEMFLO,

-4 -4

1.0 x 10 to 4.0 x 10 MULTIMED-4 -18

cm/sec SUTRA

Montana 40 to <100; 1.7 to 9 28 to 74 6 to 12in; NI 6 to >350 1x10 to 9.6x10 cm/sec 9.53 to 14 45 to 48 Not used 5 to 25K-4 -8

(vertical migration of gw:0.2-2.3 ft/yr); 1x10 to-4

8.11x10 cm/sec-8

Nevada* 40; NI NI > 6 in; compacted cover > 400 1 x 10 cm/sec (silt & clay) 4.1 NI HELP II, vers. NImaterial and 1 x 10 - 1 x 10 2.5

-8

-3 -4

cm/sec (fine sands); NI

New Mexico* 480 (East phase: 200 acres); 20 (East phase) 6 in; NI > 430 1.0 x 10 cm/sec; NI 9.56 93.95 HELP 10K and public350 hearing costs

-4

Utah 80; 20 to 25 20 to 200 6 in; compacted cover 35 to >300 1.9x10 to 6x10 cm/sec; 6 to >25 60 HELP, WHPA 18K+

material and 3 x 10 NI-3

cm/sec

-6 -9

Wyoming 40 to 47; 4 to 15 6 in; sandy, rocky loam 52 to >130 5 x 10 to 6 x 10 cm/sec 4 to 15 37 HELP NI47.5 to 273 and compacted earth

-3 -8

Note:



* Only one facility within the state has been approved for a no-migration exemtion at this time.

preparing no-migration demonstrations for …...level of detail of information required for a nmd....

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